1. Technical Field
The present invention relates to driving a load with a capacitive element, which can be applied to printing technology in which liquid droplets are discharged onto a recording medium.
2. Related Art
In the related art, a serial-type printing apparatus is proposed which discharges ink droplets onto a recording medium from a plurality of nozzles of a print head while causing a carriage, on which the print head is mounted, to move reciprocally in an intra-surface direction of the recording medium such as paper (for example, refer to JP-A-2000-343690). A control unit that is installed on a housing of the printing apparatus and the print head on the carriage are electrically connected via a flexible flat cable (hereinafter referred to as an FFC).
An electronic circuit, which generates a control signal of a predetermined waveform, is installed in the control unit that is outside of the carriage. The control signal is supplied to the print head from the control unit via the FFC. A plurality of piezoelectric elements, which discharge the ink droplets from the nozzles by deforming according to the supply of a control signal, and a plurality of switches, which control the supply and cut-off of the control signals supplied from the control unit for each of the piezoelectric elements, are installed in the print head on the carriage.
However, in order to supply a control signal of an appropriate waveform to each of the piezoelectric elements even when the number of the piezoelectric elements that are supplied with the control signal in parallel is great (when the drive load is great), it is necessary to supply a control signal with an extremely large current to the print head from the control unit via the FFC. Therefore, the power loss on the FFC is great and the waveform of the control signal is not stable. As a result, there is a problem in that the print quality is reduced. In a Large Format Printer (LFP), in which the movement amount of the carriage is great, since the total length of the FFC can reach several meters, the power loss on the FFC becomes prominent and the reduction in the print quality becomes particularly serious.